Andersen-Tawil

Leaky channels make weak muscles: Mutations in the skeletal muscle voltage-gated calcium channel (CaV 1.1) have been associated with hypokalemic periodic paralysis, but how these mutations cause the symptoms of the disorder has always been unclear. In this article the authors describe how they used mice with the CaV 1.1 mutation  to investigate how the mutation causes the features of HypoKPP.

Because this is a frequently asked question from patients we post here a reply:

Question:

My doctor wants to prescribe a medication called acetazolamide. Is that okay for someone with Hypokalemic periodic paralysis. When I look on the web it says this medication causes you to excrete potassium. How can that be good for me?

Answer:

PLoS One. 2012; 7(7): e40235.
Published online 2012 July 10.

Splicing of the rSlo Gene Affects the Molecular Composition and Drug Response of Ca2+-Activated K+ Channels in Skeletal Muscle

Maria Maddalena Dinardo,#1 Giulia Camerino,#1 Antonietta Mele,1 Ramon Latorre,2 Diana Conte Camerino,1 and Domenico Tricarico1,*

Abstract


Measuring quality of life impairment in skeletal muscle channelopathies.


Eur J Neurol. 2012 May 19. doi: 10.1111/j.1468-1331.2012.03751.x. [Epub ahead of print]

Sansone VA, Ricci C, Montanari M, Apolone G, Rose M, Meola G; INQoL Group.
Source
Department of Neurology, University of Milan, IRCCS Policlinico San Donato, Milan, Italy.


Abstract


BACKGROUND AND PURPOSE:

Puzzled by the terms membrane potential, sodium channel, potassium channel and sodium-potassium pump?  

This cute cartoon explains what each is and shows how the potassium and sodium channels, and the sodium potassium pump maintain muscle membrane potential.  Although this uses nerves to illustrate how the principle works, the action is the same in muscle membrane. Click here to watch.

Anticipating the Baby

Expectant mothers and their doctors can take the secure thought that hundreds of women with periodic paralysis have been members of our Listserv since 1995, and an overwhelming majority of them have been mothers. To date not a single one has been unable to care for her child due to her periodic paralysis.

For your convenience, arranged by topic, a "shelf" of journal articles on the periodic paralyses.

If you have a favorite link to suggest please pass it along.

Electrocardiographic Features in Andersen-Tawil Syndrome
Patients With KCNJ2 Mutations

Characteristic T-U–Wave Patterns Predict the KCNJ2 Genotype

Li Zhang, MD; D. Woodrow Benson, MD, PhD; Martin Tristani-Firouzi, MD; Louis J. Ptacek, MD;
Rabi Tawil, MD; Peter J. Schwartz, MD; Alfred L. George, MD; Minoru Horie, MD, PhD;
Gregor Andelfinger, MD; Gregory L. Snow, PhD; Ying-Hui Fu, PhD;
Michael J. Ackerman, MD, PhD; G. Michael Vincent, MD

This chapter from McGraw Hill's Myology, third edition; editors Andrew Engel and Clara Franzini-Armstrong,  give a comprehensive look at the nondystrophic myotonias and periodic paralyses, written by one of the world's top teams in the field.

Chapter from Myology, third edition: Nondystrophic Myotonias and Periodic Paralyses by Frank Lehmann-Horn, Reinhardt Rudel and Karin Jurkat-Rott.

Thank you Professor Dr. Lehmann-Horn, Dr. Jurkat-Rott and Dr. Rudel for your kind permission to include this valuable information on our website!

Do you suspect that you might have periodic paralysis? The periodic paralyses are a rare group of disorders and there are many conditions which cause an imbalance in serum potassium. So how does the doctor tell the difference between paralysis or weakness caused by an ion channelopathy and any of the other numerous disorders, conditions and reactions which might produce the same symptoms?